Our basic and clinical investigations are directed toward the better understanding, diagnosis and treatment of thromboembolic and hemorrhagic diseases, and the development of new methods for the isolation and purification of plasma proteins. A batch method recently developed in this laboratory using solid-phase polyelectrolytes permits the separation of human antihemophilic factor (AHF) from von Willebrand factor (vWF) in blood bank plasma. Using this procedure, we will prepare purified AHF and vWF to study the structure-function relationships of these proteins by classical and other biochemical techniques, which should ultimately aid in preparation of both materials for clinical use at reasonable cost. The action of vWF on platelets will also be studied in vitro: to determine its mechanism (a) in causing platelet retention in a column of glass beads; (b) in producing platelet agglutination with ristocetin; and (c) in coagulation. In conjunction with our efforts to isolate and purify plasma proteins, enzymes and inhibitors, we anticipate developing superior, solid-phase biospecific adsorbents for affinity chromatography of these materials with chloro-s-triazines (CsTs) as a general reagent for the attachment of ligands to maleic anhydride copolymers or conventional hydroxy supports (e.g., modified agarose and cellulose). We also plan to investigate the physical and chemical properties of heparin and correlate these with biologic activity; study the interactions of heparin, antithrombin and thrombin in order to clarify the mechanism of heparin-antithrombin action; and using this information, modify existing heparin purification methods to increase the yield and activity, and develop structural models for physiologically active synthetic heparinoids. BIBLIOGRAPHIC REFERENCES: Johnson, A.J.: Concentration of hepatitis-B antigen from clinical preparations of II, VII, IX and X by polyethylene glycol to enhance detection and removal. Annals N.Y. Acad. Sci., 140:162-164, 1975. Soberano, M.E., Ong, E.B., Johnson, A.J., Levy, M. and Schoellmann, G.: Evidence for an essential serine residue in the heavy chain of urokinase purified by affinity chromatography. Fed. Proc. 34:860, 1975.